A photochromic eyeglass has such properties that in the outdoors where lights including ultraviolet ray such as sunlight are irradiated, its lens colors speedily and thereby it functions as a sunglass, while in the interior where such lights are not irradiated, its lens discolors and thereby it functions as a normal eyeglass. The demand of the photochromic eyeglass has been increased in recent years.
Known examples of a process for producing a plastic lens having photochromic properties are a method for impregnating the surface of a lens having no photochromic properties with a photochromic compound (hereinafter referred to impregnating process), a method of coating the surface of a plastic lens with a coating agent which comprises a curable composition having photochromic properties (hereinafter referred to photochromic coating agent) and then curing, and thereby providing a resin layer having photochromic properties (photochromic coat layer) (hereinafter referred to coating method), and a method for producing a photochromic lens directly by dissolving a photochromic compound in a monomer and polymerizing them (hereinafter referred to in-mass method). Among these methods, the coating method has an advantage capable of simply giving photochromic properties to any lens substrates in principle as compared with the other two methods. For example, in the impregnating method, it is necessary to use a soft substrate in which a photochromic compound can be easily diffused, as a substrate lens. In the in-mass method, it is necessary to use a special monomer composition in order to exhibit good photochromic properties. However, the coating method does not have such a restriction on substrates.
As a process for producing a photochromic lens by the coating method, there is a known method of using, as a photochromic coating agent, a curable composition which comprises a radical polymerizing monomer containing a radical polymerizing monomer having a silanol group or a group capable of generating a silanol group by hydrolysis, an amine compound, and a photochromic compound in specific amounts (referred to Patent Document 1). There is, furthermore, a known method of using, as an adhesive primer, a polyurethane resin layer which comprises a cured material of a moisture curable polyurethane resin and/or its precursor in order to improve adhesion in the case of using the photochromic coating agent (referred to Patent Document 2). When a photochromic coating lens is produced by using the composition described in Patent Document 1 as a photochromic coating agent and directly applying the composition on a substrate, the adhesion of a photochromic coat layer with some kinds of substrates is sometimes lowered and come away in an accelerated test with boiling that high temperature and high humidity conditions are assumed. When the above adhesion primer is used, the adhesion is improved and thereby film separation can be prevented.    Patent Document 1: International Publication 03/011967 Pamphlet    Patent Document 2: International Publication 04/078476 Pamphlet